Spin polarized current has been widely used in spintronic devices. Recent trends indicate pure spin current would be even better for spintronics. For example, a great deal of attention has been focused on pure spin current because of its unique attribute of carrying substantial angular momentum with minimal charge carriers, thus generating much less Joule heat. However, a pure spin current cannot be generated by the usual electrical means except through a few mechanisms, among them spin Hall effect (SHE), lateral spin valve, spin pumping, and spin Seebeck effect (SSE), by exploiting heavy (high-Z) metals with strong spin-orbit coupling (SOC) for the generation or detection of the pure spin current.
The most widely used method for detecting a pure spin current is the inverse spin-Hall effect (ISHE) that converts spin current back into a charge current. To date, ISHE has been demonstrated only in a few non-magnetic metals with strong spin orbit coupling, such as Pt and Au. Such non-magnetic metals have, therefore, been used as pure spin current generators and detectors, but at a very high material cost.
For example, U.S. Pat. No. 8,604,571, the entire contents of which are incorporated by reference in herein in their entirety, discloses a thermoelectric conversion device that includes a nonmagnetic inverse spin-Hall effect material, for example, Pt, Au, Pd, Ag, Bi or an element having an f-orbital, with a spin-wave spin current generating material made of a magnetic dielectric material.
Additionally, in International Publication Number WO 2013/025994, the entire contents of which are incorporated by reference herein in their entirety, discloses a device with a spin-Hall base layer comprising a non-magnetic conductor, and a free layer that contacts the spin Hall effect layer wherein the spin Hall base layer comprises a non-magnetic conductor material
What is needed in the art are spintronics devices, such as spin current generators and detectors, that offer higher spin and charge conversion efficiency and much lower cost.